Which term describes a refractive condition in which parallel rays do not focus on the retina?

Which term describes a refractive condition in which parallel rays do not focus on the retina?

• A. Astigmatism
• B. Ametropia
• C. Aphakia
• D. Presbyopia

Answer: (B)

When light from distant objects enters the eye, it should be focused on the retina. If parallel rays do not converge there, the eye has ametropia, a refractive error describing any deviation from proper focus on the retina. This umbrella term includes conditions where the focal point lies in front of the retina (myopia) or behind it (hyperopia), among others. The other terms refer to more specific situations: astigmatism involves uneven focusing due to irregular curvature, aphakia is the absence of the lens, and presbyopia is age-related loss of accommodation. So the description of parallel rays not focusing on the retina fits ametropia.

When light from distant objects enters the eye, it should be focused on the retina. If parallel rays do not converge there, the eye has ametropia, a refractive error describing any deviation from proper focus on the retina. This umbrella term includes conditions where the focal point lies in front of the retina (myopia) or behind it (hyperopia), among others. The other terms refer to more specific situations: astigmatism involves uneven focusing due to irregular curvature, aphakia is the absence of the lens, and presbyopia is age-related loss of accommodation. So the description of parallel rays not focusing on the retina fits ametropia.